覆膜砂多孔结构激光3D打印成形精度试验研究

Experimental research on laser 3D printing forming accuracy of porous structure of coated sand

以激光功率、扫描速度、扫描间距、层厚、层间冷却时间等工艺参数为主要因素,进行了覆膜砂多孔结构成形工艺正交试验。研究了工艺参数对砂面温度以及蜂窝、G曲面、W点阵等3种多孔结构成形件精度的影响。结果表明:砂面温度受热积累作用而逐层升高,不同高度处成形尺寸会因此产生差异,其中层间冷却时间对砂面温度影响最大;多孔结构孔隙越小,分布越密集,越容易产生次级烧结现象。层间冷却时间对蜂窝结构和W点阵结构的尺寸精度影响最大,激光功率对G曲面结构的尺寸精度影响最大。

Taking laser power, scanning speed, scanning distance, layer thickness, inter-layer cooling time and other process parameters as the main factors, an orthogonal test of the forming process of the porous structure of coated sand has been carried out. The influence of process parameters on the temperature of the sand surface and the precision of three porous structures such as honeycomb, G surface and W lattice has been studied. The results show that the temperature of the sand surface increases layer by layer due to the accumulation of heat, and the forming size at different heights will vary accordingly. The cooling time between layers has the greatest influence on the temperature of the sand surface;the smaller the pores of the porous structure, the denser the distribution, and the easier it is to produce secondary sintering phenomenon. The inter-layer cooling time has the greatest influence on the dimensional accuracy of the honeycomb structure and the W lattice structure, while the laser power has the greatest influence on the dimensional accuracy of the G curved surface structure.